Duffels are rectangular bags with handles and typically a shoulder strap. Duffels are often made of nylon or leather and used for short trips or commonly used as a Gym Bag.
About Ripstop Nylon:
Ripstop Nylon is a synthetic fabric woven with a reinforced double thread of very fine nylon fibers in rectangular intervals which give this fabric the distinctive small square appearance. Ripstop Nylon is lightweight, durable, and tear and abrasion resistant.